Heat oven to 375 degrees. Combine flour, sugar, salt, and baking powder in a large mixing bowl. Slowly stir in beer and mix just until combined. Batter will be thick. Spread in a greased 8-inch loaf pan and bake until golden brown and a toothpick stuck in the center comes out clean, about 45 minutes. Cool in the pan on a rack for 10 minutes. Remove from pan and cool 10 more minutes. Serve warm or at room temperature.
You can add flavor variations if you are so inclined --
Garlic & Herb: Add 1 teaspoon dried rosemary, 1 teaspoon dried oregano, 1 teaspoon dried thyme, and 2 minced garlic cloves (or 1 teaspoon garlic flakes) to the basic mix. For fresh herbs, use 1 chopped Tablespoon of each.
Dill & Chive: Add 2 Tablespoons chopped fresh dill (or 2 teaspoons dried dill) and 1/4 cup chopped fresh chives to the basic mix.
Italian: Add 1 teaspoon each dried basil and oregano (or 1 Tablespoon each chopped fresh basil and oregano), 2 minced cloves of garlic and 1 tablespoon of minced sundried tomatoes to the basic mix.
Other Additions: Any dried or fresh herbs; 1/2 cup finely chopped onion, 1/2 cup chopped scallions; 1/2 cup chopped fresh parsley, 1/2 cup whole wheat flour or 1/2 cup oats in place of 1/2 cup of the all-purpose flour.